Speaking as Prof Hawking prepares to celebrate his 70th birthday tomorrow, Prof Cox said: “In terms of popularising physics, I wouldn’t be doing what I do now were it not for him.”
Prof Cox added: “I was 20 and in a band when he published A Brief History Of Time.
“I was fascinated by physics and it was one of the few books around at the time which really addressed that fascination.
“He was a big influence on me, as he was on anyone of that age who was interested in physics.”
Prof Cox, best-known for presenting BBC science programmes and for his work on the Large Hadron Collider, said the only person who rivalled Prof Hawking in terms of popular appeal was American physicist Richard Feynman.
He added: “Stephen is one of only a handful of people in this field – whom I do not count myself among – who are genuine Nobel Prize contenders.
“He also realises that it is not just our job to ‘do’ physics but to explain it as it is something which fascinates people.”
While recognising that Prof Hawking’s condition, a form of motor neurone disease, was part of his public image, Prof Cox said it was not integral to his popularity.
He added: “A Brief History Of Time was published before people knew who Stephen was and was successful on its own merits.
“However, if you spoke to Stephen himself, he would say that he considered himself a fairly average scientist whose condition provided an opportunity to focus on his work.
“One thing he told me was that he spends a great amount of time theorising as he gets in and out of the bath, simply because it takes so long.”
Professor Martin Rees, Astronomer Royal and Master of Trinity College Cambridge, also paid tribute. He said: “When I first met Stephen Hawking we were both research students and it was thought that he might not live long enough even to finish his PhD degree. But, amazingly, he has reached the age of 70. Even mere survival would have been a medical marvel, but of course he hasn’t merely survived, he has become arguably the most famous scientist in the world – acclaimed for his brilliant researches.
“Astronomers are used to large numbers. But few numbers could be as large as the odds I’d have given, back in 1964 when Stephen received his ‘death sentence’, against ever celebrating this uniquely inspiring crescendo of achievement.”